1. Field of the Invention
The present invention relates generally to the winding of armatures for electric motors, generators and the like by means of a flier-type armature winder. More particularly, the invention relates to a method of looping armature coil leads about commutator tangs.
2. Description of the Prior Art
Those versed in the prior art dealing with the subject of armature winding are familiar with flier-type armature winders for winding armatures of the type having a commutator with circumferentially gapped tangs and a slotted armature core, both mounted in axially spaced relation on a common shaft. In operation, the armature winding machine successively winds coils of wire into pairs of slots in the armature core and loops wire leads between the wound coils about corresponding ones of the commutator tangs. A well known example of such an armature winder is disclosed in U.S. Pat. No. 3,713,598, granted Jan. 30, 1973. While a pair of fliers are rotated in opposite directions to individually wind coils of wire onto the armature core, the stretch of wire between each flier and the armature core is prevented from accidentally engaging one of the commutator tangs by a shield which covers the tangs. After each winding of a pair of wire coils by the two fliers, the shield is rotated about the commutator tangs to substantially expose two of the tangs respectively through a pair of slots in the shield. The fliers are then rotated in directions opposite to their directions for winding the wire coils to partially loop the wire leads, between the last wound coils and the fliers, respectively about the exposed tangs. To complete looping of the wire leads about the exposed tangs, the shield is first rotated to cover these tangs and then the fliers are rotated in their winding directions to form the remainder of the wire loop. Covering the exposed tangs before rotating the fliers prevents the wire leads from slipping over the tops of the tangs as the wire leads are pulled forward by the rotated fliers.
It will be observed in this kind of flier-type armature winder, that it is the winding fliers which loop the wire leads from the last wound coils about corresponding ones of the commutator tangs. For many applications, the winding fliers may successfully perform this function. At times, however, the design of the commutator or the character of the wire, particularly heavy wire, is such that the wire leads are not easily looped about the corresponding tangs by the winding fliers. Consequently, as for example disclosed in the earlier cited U.S. Pat. No. 3,713,598, movable guide members have been devised to guide the wire leads about the commutator tangs. While these guide members may be successfully employed, they occasionally can snag the wire leads during rotation of the winding fliers.
A somewhat different approach to armature winding with a flier-type armature winder involves the use of an inner commutator shield and an outer commutator shield, rather than winding fliers, to loop the wire leads about the commutator tangs. Such an approach has been used for several years in a Globe Armature Winder, Model HFA 1-A. According to this approach, between each successive winding of an armature coil by a flier, the flier is rotated in a direction opposite to its direction for winding coils to lay a wire lead from the last wound coil against the outer shield. The inner shield is then rotated to position a slot in its peripheral end portion over a first one of first and second gaps in the commutator, the gaps being disposed at opposite sides of a commutator tang which corresponds to the last wound coil. The outer shield is then rotated about the inner shield until a projecting fin member of the outer shield pushes the wire lead immediately over the slot in the inner shield; whereupon, an intermediate portion of the wire lead drops through the slot into the first gap. The inner shield is then rotated to move its slot with the wire lead from their location over the first gap to another location over the second gap, i.e., the next succeeding gap alongside the corresponding tang. Such rotation of the inner shield bends a trailing portion of the wire lead completely across a rear face of the corresponding tang. Then, the outer shield is rotated again to cause an inclined edge of the outer shield to push the wire lead out of the slot in the inner shield; whereupon, an open loop is formed about the corresponding tang.
While flier-type armature winders which include cooperating inner and outer shields for looping the wire leads about the commutator tangs have been used for a number of years, it will be recognized that such winders suffer from several disadvantages. For example, the inclined edge of the outer shield (which pushes the wire lead out of the slot in the inner shield) may cooperate with the slot defining edges of the inner shield in the manner of a scissors to cut the wire lead while it is in the slot. Moreover, the insulation covering of the wire lead may flake off in parts which can find their way between the inner and outer shields to eventually jam these shields.